are they very gnostic believers if so of course its not going to be very fun for them to hear that maybe just let it be until it comes up a little more naturally in conversation as far as i know in the christian religion the role of the parents are to teach and practice with their kids under the church until they are adults in the church and thats all they can do im not sure if there is a similar thing in the muslim faith but all you can do is tell them your opinions and there isnt really anything they can do to change that